459 research outputs found
Theoretical advances on Economic Model Predictive Control with time-varying costs
© 2016 Published by Elsevier Ltd on behalf of International Federation of Automatic Control.Economic Model Predictive Control is a technique for optimization of economic revenues arising from controlled dynamical processes that has established itself as a variant of standard Tracking Model Predictive Control. It departs from the latter in that arbitrary cost functions are allowed in the formulation of the stage cost. This paper takes a further step in expanding the applicability of Economic Model Predictive Control by illustrating how the paradigm can be adapted in order to accommodate time-varying or parameter-varying costs
Imaging of biliary involvement in sarcoidosis: Computed tomography, magnetic resonance cholangiopancreatography, and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging findings
Sarcoidosis is a multisystem disease usually affecting the chest, hilar lymph nodes, and lungs, but can potentially involve any organ; therefore, its clinical presentation may vary. Hepato-biliary involvement is rare, and typically asymptomatic; however, it can lead to cirrhosis, and may require liver transplantation. In this report, we present a rare case of a patient affected by sarcoidosis with hepatobiliary involvement. He presented to our hospital complaining of dyspnea triggered by moderate efforts and oppressive thoracic discomfort. Chest X-ray showed multiple bilateral nodular opacities and enlargement of both hilar regions, confirmed by a subsequent total-body computed tomography scan and positron emission tomography, which also revealed cardiac, splenic, and hepatic involvement. Liver function was studied via gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging, and magnetic resonance cholangiopancreatography (MRCP) was also performed. The diagnosis of sarcoidosis was finally achieved via liver biopsy, revealing non-necrotizing granulomas in the periportal space. The patient was treated with prednisone per os, with regression of all lesions at all levels. Although other cases of biliary sarcoidosis have been described, this report provides a complete image set of Gd-EOB-DTPA-enhanced magnetic resonance and MRCP images that is lacking in the English literature, and which may be useful for diagnosis
Chiral recognition between 1-(4-fluorophenyl)ethanol and 2-butanol: higher binding energy of homochiral complexes in the gas phase
Diastereomeric adducts between (S)-1-(4-fluorophenyl)-ethanol and R and S 2-butanol, formed by supersonic expansion, were studied by a combination of mass selected resonant two-photon ionization-spectroscopy and IR depletion spectroscopy. Chiral recognition is evidenced by the specific spectroscopic signatures of the S1 S0 electronic transition as well as different frequencies and intensities of the OH stretch vibrational mode in the ground state. D-DFT calcns. were performed to assist in the anal. of the spectra and the detn. of the structures. The homochiral and heterochiral complexes show slight structural differences, in particular in the interaction of the alkyl groups of 2-butanol with the arom. ring. The homochiral [FESBS] complex is more stable than the heterochiral [FESBR] diastereomer in both the ground and excited states. The binding energy difference was evaluated to be >0.60 kcal mol-1
Exchange-coupled bimagnetic cobalt/iron oxide branched nanocrystal heterostructures.
A colloidal seeded-growth strategy, relying on time-programmed delivery of selected stabilizing surfactants, has been developed to synthesize bimagnetic hybrid nanocrystals (HNCs) that consist of a single-crystal tetrapod-shaped skeleton of ferrimagnetic (FiM) iron oxide functionalized with multiple polycrystalline spherical domains of ferromagnetic (FM) Co. Due to the direct bonding interfaces formed between the two materials at the relevant junction regions, the HNCs exhibit FiM-FM exchange coupling, which transcribes into a rich scenario of significantly modified properties (not otherwise achievable with any of the single components or with their physical mixtures), including higher saturation magnetization and coercitivity values, exchange biasing, and enhanced thermal stability due to induced extra anisotropy. The availability of these new types of HNCs suggests that development of appropriate synthetic tools for arranging distinct material domains in predetermined spatial arrangements could lead to ..
3D characterization of CdSe nanoparticles attached to carbon nanotubes
The crystallographic structure of CdSe nanoparticles attached to carbon
nanotubes has been elucidated by means of high resolution transmission electron
microscopy and high angle annular dark field scanning transmission electron
microscopy tomography. CdSe rod-like nanoparticles, grown in solution together
with carbon nanotubes, undergo a morphological transformation and become
attached to the carbon surface. Electron tomography reveals that the
nanoparticles are hexagonal-based with the (001) planes epitaxially matched to
the outer graphene layer.Comment: 7 pages, 8 figure
Stimulation of beta2-adrenergic receptor increases CFTR function and decreases ATP levels in murine hematopoietic stem/progenitor cells
Electron and ion spectroscopy of azobenzene in the valence and core shells
Azobenzene is a prototype and a building block of a class of molecules of extreme technological interest as molecular photo-switches. We present a joint experimental and theoretical study of its response to irradiation with light across the UV to x-ray spectrum. The study of valence and inner shell photo-ionization and excitation processes combined with measurement of valence photoelectron-photoion coincidence and mass spectra across the core thresholds provides a detailed insight into the site- and state-selected photo-induced processes. Photo-ionization and excitation measurements are interpreted via the multi-configurational restricted active space self-consistent field method corrected by second order perturbation theory. Using static modeling, we demonstrate that the carbon and nitrogen K edges of azobenzene are suitable candidates for exploring its photoinduced dynamics thanks to the transient signals appearing in background-free regions of the NEXAFS and XPS
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